The overall objective of this project is to study mechanisms of cancer induction in experimental animals. We are attempting to obtain some evidence that rat bladder epithelial cells can metabolize the bladder carcinogen butyl(4-hydroxybutyl)nitrosamine, and if so to attempt to determine whether any of these metabolites are reactive with cellular macromolecules. BIBLIOGRAPHIC REFERENCES: R. Cox and C. C. Irving, Damage and Repair of DNA in Various Tissues of the Rat Induced by 4-Nitroquinoline-1-oxide. Cancer Res., 35, 1858-1860 (1975). C. C. Irving, Comparative Toxicity of N-Hydroxy-2-acetylaminofluorene in Several Strains of Rats. Cancer Res., 35, 2959-2961 (1975).